ExtractFileName

Function ExtractFileName( const FileName : string) : string

Example

procedure ScriptEvent(var Value: variant);
begin
  Value := ExtractFileName('C:\Fictional\Inbound\order.csv');
  // order.csv
end;

Usage

ExtractFileName returns the name and extension after the final path or drive delimiter.

Parameters

Name	Type	Description
FileName	string, const	File-name or path text to parse.

Returns

The name-and-extension suffix. If no recognised delimiter exists, the complete input is returned.

Behaviour

• 'C:\Folder\report.csv' returns 'report.csv'.
• 'C:report.csv' also returns 'report.csv'.
• 'report.csv' is returned unchanged.
• A path ending in a recognised delimiter returns an empty string.
• Dots are not special to this routine; use ExtractFileExt to separate the extension.

Errors

There is no normal content-dependent exception. String conversion and allocation failures can propagate.

Usage notes

Treat the result as untrusted when the input came from outside the configuration. Removing a directory prefix does not make a name safe for local file creation; validate it against the target path policy.

Additional Technical Info

ExtractFileName returns the part of FileName after its final recognised path or drive delimiter. The returned value includes any extension.

The example is source-reviewed and was not executed by the documentation workflow. The path does not need to exist.

Implementation

The Velox wrapper calls installed System.SysUtils.ExtractFileName. On Windows the RTL locates the last backslash or drive colon and copies everything after it. It does not call the file system.

Edge cases and quirks

• On the current Windows build, forward slash is not part of the delimiter set. Mixed or URL-style input may be returned with slash-separated prefixes still attached.
• UNC and extended prefixes are handled only because their final backslash is recognised; no network syntax validation occurs.
• . and .. path segments are not resolved.
• The return can contain characters that are invalid in a Windows file name because this is only lexical parsing.
• An empty input returns an empty string.

Side effects

None.

Performance and concurrency

The routine scans backward and copies the suffix. It is linear in path length and has no mutable shared state.

Related entries

• ExtractFilePath returns the complementary prefix including its delimiter.
• ExtractFileDir returns a directory-style prefix.
• ExtractFileExt returns only the extension.
• MakeSafeFilename is a separate Velox-owned transformation.

External references

• Embarcadero System.SysUtils.ExtractFileName
• Free Pascal ExtractFileName - compatible API context; the installed Windows Delphi delimiter set defines Velox behaviour.

Created 2026-07-15